The present invention relates to a control apparatus for controlling a vehicle drive system that has a fluid coupling including a direct connection clutch, and a transmission, and that outputs rotation of an input member that is drivingly connected to an engine and a rotating electric machine to an output member.
In recent years, hybrid vehicles using both an engine and a rotating electric machine as driving force sources to achieve improved fuel economy and reduced exhaust emissions of the engine are put into practical use. As an example of a vehicle drive system used for such a hybrid vehicle, Japanese Patent Application Publication No. JP-A-2003-278910 detailed below, for example, describes a vehicle drive system that has a fluid coupling including a direct connection clutch, and a transmission, and outputs rotation of an input member that is drivingly connected to an engine and a rotating electric machine to an output member via the fluid coupling and the transmission.
In the vehicle drive system described in Japanese Patent Application Publication No. JP-A-2003-278910, when an accelerator opening is brought into a fully closed position as operated according to the intention of the driver of the vehicle, a control apparatus controls the direct connection clutch into an engaged state, regardless of whether the direct connection clutch is in the engaged state or a disengaged state. At the same time, a shift speed of the transmission is upshifted in order to keep energy consumed by engine braking low by decreasing the speed of the engine and improve energy regeneration efficiency. As such, a situation can occur in which an upshift operation of the shift speed is requested at timing substantially equal to timing at which an engagement operation of the direct connection clutch is requested.
Under these circumstances, the vehicle drive system described in Japanese Patent Application Publication No. JP-A-2003-278910 is controlled such that the direct connection clutch is kept in the disengaged state while the upshift operation of the shift speed is being performed and the direct connection clutch is engaged after the upshift operation is completed. This reduces impact on the vehicle caused by shifting (shift shock).